Duplex heater



Dec. 18, 1951 E N 2,578,927

DUPLEX HEATER Filed June 4, 1948. 4 Sheets-Sheet l 'IIIIIIIIII- I n H v I I 89 I" III "In I Dec. 18, 1951 r E 5550 7 2,578,927

1 DUPLEX HEATER Filed June 4, 1948 4 Sheets-Sheet 3 ZSnnentor [ow/N fssa/v (momei 5 Dec. 18, 1951 Filed June X4; 1948 E. SSS-ON 2,578,927

DUPLEX HEATER 4 Sheets-Sheet 4 "mull-I- 3nventor (Ittorneg S Patented Dec. 18, 1951 DUPLEX HEATER Edwin Esson, Kansas City, Mo., .assignor to Locke Stove Company,- Kansas City, Mo., a corporation of Missouri Application June 4, 1948, Serial No. 31,171

3 Claims. (01. 126-67) This invention relates to duplex heaters adapted to burn different types of fuels depend-- ing upon which fuel is the most readily available or less expensive. For example, in some communities a specific fuel supply becomes uncertain because of excess demand, failure in transportation or other causes so as to make it necessary to shift to a type of fuel which is available. When the shift is from a fluid fuel to a solid fuel, the heating equipment is a problem because iiuid fuel burners are completely useless for burning solid fuels and fluid fuels cannot be burned in solid fuel burners. It is, therefore, desirable to provide a heater having separate fuel burning units located in separate combustion chambers but this is objectionable because each unit must be equipped with its own radiating surfaces and in the circulation type of heater provision must be made to pass the air to be heated in contact with the radiating surface of the heating unit which is in operation but this has further disadvantage in that radiating surfaces at the best are restricted and insufiicient to heat the air with best efficiency and when the heating surface of each unit is made sufficiently large to heat the desired volume of air, the overall size of the heater is so large and occupies so much space that the heater is not practical or saleable.

It is therefore, the principal object of the present invention to provide a duplex heater wherein the radiating surfaces of both units are utilized for heating circulated air through the provision of means for passing hot products of combustion from a burner unit in operation into contact with the radiating surface of the other unit. Thus, the combined, radiating capacities of both units are used to eficiently heat the required volume of air and permit a compact, small-sized heater having a size which permits ready installation in an available space.

Other objects of the invention are to provide the fluid fuel burner unit with means for protecting the burner from fly ash which is carried. by the products of combustion from the solid fuel burning unit; to provide a duplex heater with interconnected combustion chambers and a common vent which is adapted for direct connection with one or the other units so as to divert Products of combustion from the burner in operation to the combustion chamber for the burner which is not in operation; and to pro-=- vide means for shutting off the supply of combustion supporting air to the burner unit which is not in use so as to avoid an excess of air and prevent unnecessary cooling of the unit in which the burner is out of use.

In accomplishing these and other objects of the invention, I have provided improved structure, the preferred form of which is illustrated in the accompanying drawing wherein:

Fig. 1 is a perspective view of a duplex heater constructed in accordance with the present invention, parts of which are broken away to better illustrate the inner construction.

Fig. 2 is a vertical section through the heater, particularly illustrating the relative arrangement of the different fuel burning units.

Fig. 3 is a cross section on the line 3-3 of Fig. 2.

Fig. 4 is a perspective view of the vent connection between the combustion chambers of the respective units and the damper for selectively controlling flow of products of combustion fro one or the other of the units.

Fig. 5 is a partial horizontal view through the heater on the line 5-5 of Fig. 3.

Fig. 6 is a fragmentary section on the line 6Ei of Fig. 2, particularly illustrating the inlet to the flue within a wall of the fuel magazine.

Referring more in detail to the drawings:

-l designates a duplex heater constructed in accordance with the present invention and which includes a base 2 for supporting a casing or cabinet 3 enclosing a fluid fuel burning unit 4 and a solid fuel burning unit 5. The units 4 and 5 are mounted in juxtaposition on the base 2 and comprise separate casings 6 and l. The casings 6 and 'i may be of any suitable shape to accommodate a fluid fuel burner 8 and a solid fuel fire box 9 respectively and to provide combustion chambers l8 and I! having combined radiating surfaces sufficient to efficiently heat the air that is to be circulated through the cabinet as later described.

In the illustrated instance the casing 6 comprises a burner compartment l2 that may be of substantially cylindrical form and which has a bottom 53 that is provided with an air inlet opening It for passage of combustion supporting air. The top of the burner compartment is covered by a plate It to mount the combustion chamber H] which is shown as comprising substantially plane side walls it, l1, l8 and I9 and a top 20. The plate 15 includes a ring 2| for supporting a fluid fuel burner 22.

In the illustrated instance the burner is of pot type and includes an annular wall 23 of smaller diameter than the wall forming the burner chamber to provide an annular flow passageway 24 for directing air admitted through the opening I4 through a plurality of perforations 25 that are formed in the wall of the pot. The burner pot has a closed bottom 26 that is spaced above the opening l3 to provide a passageway to the annular space 24. The burner pot has a fuel inlet 2'! that is connected by a duct 28 leading to a constant level and fuel control valve 29 mounted on a side wall of the casing as shown in Fig. 3 and which is supplied with fuel from a supply tank 30 through a pipe 3|. The burner pot is also provided with .the usual low fire ring 32 and a high fire ring 33.

In carrying out the invention, the opening 34 in the high fire ring of the burner pot is adapted to be closed by a cover 35 which is pivoted to the high fire ring by hinge elements 36 so that the cover may be swung from a position in covering 4 openings 13 and 14. The sections also include end walls 15 and 16, each having one-half of a flue collar 11 therein so that when the sections are secured together in juxtaposition a continuous collar is formed to connect with a vent pipe 18 extending through an opening 19 of the cabinet and leading to a suitable chimney (not shown). Each section is provided with a flange 80 that is secured about the openings in the respective casings by welding or the like. The abutting edges of each section are provided with registering notches 8| and 82 to journal a shaft 83 that car- 'ries a damper 84. The shaft extends upwardly above the top of the heating units and connects with an actuating lever 65 having an outer end 86 projecting through a slot-like opening 81 in r the front wall of the cabinet as best shown in relation with the opening to an out of way position against the wall of the combustion chamber. The cover is preferably provided with a handle 38 that is located in convenient reach of an inspection opening 39- formed in the side wall 6 0f the combustion chamber. The inspection opening 39 is normally closed by a door 49 having an opening 4! normally closed by a cover 4-2. The cover 42 is adapted to be moved out of closing relation with the opening 4| so as to permit access to the handle 38 for moving the cover 35 to and from covering relation with the opening 34. Access is had to the door through a removable panel 43 in the cabinet. The side wall I! of the combustion chamber has laterally spaced openings 44 and 45 that are connected with the openings 46 and 41 in the adjacent wall of the combustion chamber l I of the casing.

The casing l of the solid fuel burning unit is shown of substantially rectangular cross section conforming to the cross section of the combustion chamber of the fluid fuel burning unit and has corresponding walls 48, 49, 50 and 5i, the wall 48 having the openings 46 and 41 spaced from the wall I! to provide an air passageway 52 therebetween.

The casing 'i is provided with a top 53 and a bottom 54. Carried above the bottom 54 is a grate 55 and extending thereabove is a fire resistant lining 56 for portions of the respective walls to provide a fuel magazine 51. for the side Walls 49 and 5| are designed to provide flues 58 having connection with the interior of the magazine through inlet openings 59 (Fig. 6) and outlets 50 above the magazine (Fig. 5). The linings terminate below the top and the side wall 50 which has a door opening 6| normally closed by a door 62 that is accessible through a removable panel 53 in the adjacent side wall of the cabinet 3. The adjacent side walls I? and 48 of the respective combustion chambers have the registering openings 44 and 46 interconnected across the passageway 52 by collars 64 so that products of combustion generated in either heating unit may pass through the combustion chamber of the other heating unit. The other openings 45 and 41 connected with a common flue outlet 65 formed as a part of a damper housing 66. The damper housing consists of sections 61 and 88 each of which includes a substantially triangular-shaped upper and lower horizontal wall 69 and i0 having abutting edges joining midway between the passageway 52 as best shown in Fig. 5. The walls 69 and T0 of the sections are interconnected by vertical walls H and 12 that extend diagonally across the corners of the combustion chambers and which are provided with The linings Figs. 3 and 4. The damper is adapted to be moved into closing relation with either one or the other of the openings 13 or 14 depending upon which of the heating units is to be in operation. The outer cabinet has the side walls thereof spaced from the heating units to provide air passageways 88 for the circulation of air that is admitted into the cabinet through bottom louver B9 and which is discharged through louvers 90 in the top of the cabinet in the same manner as any conventional circulating heater. Draft is supplied to the solid fuel burning unit through the usual damper Si in the door of an ash compartment 92 that is provided below the grate.

Assuming that the heater is constructed and assembled as described and that the heater is to be operated on solid fuel, fuel is supplied to the magazine of the solid fuel burning unit 5 through the door 62 and a fire is started on the grate 55. During this time the damper may be swung into closing relation with the flue outlet of the fluid fuel burning unit so as to effect a strong draft through the solid fuel burning unit until the fire is started. If the door 40 covering the outlet opening in the fire ring of the burner pot has not been closed, it is closed to prevent fly ash from getting into the burner pot and also to close off admission of air by way of the burner pot. The damper 84 is then moved so that it closes the flue outlet opening 14 in the solid fuel burning unit 5 whereupon the draft is transferred through the openings 44 and 46, combustion chamber ID of the fluid fuel burning unit 4 and flue outlet opening 4'! to the flue connection 55. The products of combustion rising within the solid fuel burning unit heat the walls thereof to heat the air that travels through the air passageways 88 immediately surrounding the solid fuel burning unit. The hot products of combustion then pass through the combustion chamber IU of the fluid fuel burning unit to heat the walls thereof for transmitting heat to the air that is circulated immediatiely around the fluid fuel burning unit H). the combustionchamber walls of both heating units are utilized when heating the air circulatedv through the outer cabinet. When it is desired to operate the fluid fuel burning unit, the draft connections for the solid fuel unit are closed and the damper 84 is moved to close the opening 13. The firepot cover door 35 is then swung to open position, after which fuel is admitted to the flrepot 22 and ignition is effected to heat the walls of the combustion chamber with the resulting hot products of combustion. Since the damper closes direct outlet through the flue connection the gases escape through the openings 44 and 46 by way of the It is thus obvious that 5 combustion chamber I l of the solid fuel burning unit to heat the walls of that unit. The radiating surfaces of both units are again available to heat the air under circulation through the cabinet of the heater.

From the foregoing it is obvious that I have provided a duplex heater. that is of simple and compact construction and which efficiently heats the air under circulation through utilization of the heat transmitting surfaces of both units by eifecting circulation of the products of combustion through both combustion chambers regardless of which unit is'burning the fuel.

What I claim and desire to secure by Letters Patent is:

1. A duplex heater including a casing, a fluid fuel burning unit in the casing having a combustion chamber and a burner pot chamber adapted to contain a burner pot and having an outlet into the combustion chamber, means for closing said outlet when the burner pot is not in operation, a solid fuel burning unit in the casing having a combustion chamber, means forming separate outlets for discharge of products of combustion from the combustion chambers, means forming an interconnecting passageway between said combustion chambers for passing products of combustion from one unit to the other, and means for closing the outlet of the combustion chamber for the solid fuel burning unit and opening the outlet to the other combustion chamber to effect flow of roducts of combustion through the other unit.

2. A duplex heater including a casing, a fluid fuel burning unit in the casing having a combustion chamber and a burner pot chamber adapted, to contain a burner pot and having an outlet into the combustion chamber, means for closing said outlet when the burner pot is not in operation, a solid fuel burning unit in the casing having a combustion chamber, means forming separate outlets for discharge of products of combustion from the combustion chambers, means forming an interconnecting passageway between said combustion chambers for passing products of combustion from one unit to the other, means for closing the outlet of the combustion chamber of the solid fuel burning unit and opening the outlet to the other combustion chamber to eifect flow of products of combustion through the other unit, means for supplying combustion supporting air to the solid fuel burning unit, and means for controlling said air supply.

3. A duplex heater including a casing, a pair of separate fuel burning units in the casing, each unit having a combustion chamber provided with a flue outlet opening, a duct directly connecting the combustion chamber of one unit with the combustion chamber of the other unit, said duct being independent of the flue outlet openings, damper means for selectively closing one or the other of the flue outlet openings whereby the unit having the closed flue outlet opening may be used for passing products of combustion directly into the combustion chamber of the other unit through said duct to utilize radiating surfaces of both combustion chambers when only one or said units is in use.

EDWIN ESSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 299,881 Topliif et al. June 3, 1884 782,607 Masseth et al Feb. 14, 1905 1,615,236 Schellhammer Jan. 25, 1927 1,857,480 Schonberger May 10, 1932 1,877,421 Munkel Sept. 13, 1932 

